Traditional Japanese music is still being played today in theaters and plays.

For example Nagauta (長唄) is a form of traditional Japanese music using the shamisen (Japanese stringed instrument).

http://www.youtube.com/watch?v=qZajZ8w82xM&feature=related

Gagaku (雅楽) is formal music played for the imperial court. Gagaku is the oldest type of traditional music in Japan.

Jōruri (浄瑠璃) is a type of music that accompanies a narrative storytelling event; much like the plays found in Japanese theater.